This invention relates to spa nozzles having air entrainment and more particularly to fluidic spa nozzles having air entrainment.
It is common practice to provide an air line to spa nozzles for aeration of exhausting water. The air typically is drawn by the water through the venturi effect of the flowing water, and sometimes air is supplied under pressure from an air pump. See U.S. Pat. Nos. 5,495,627, 5,457,825, 5,444,879 and 5,238,585.
The present invention is directed to a method and apparatus for increasing entrainment volume. The invention is directed to an air entrainment spa nozzle wherein a jet of water passes over an air entrainment port and air entrainment is enhanced by a ramp surface extending in a downstream direction from the air entrainment port. In a preferred embodiment, a fluidic oscillator causes sweeping motions of the jet of water and has a pair of control ports immediately downstream of the power nozzle. In one embodiment, the control ports are part of a crossover-type fluidic oscillator having feedback passages, and the entrainment port is located at the exit of an oscillation chamber. In another fluidic embodiment, an inertance loop interconnects the control ports to induce oscillation of the jet of water, and the air entrainment port is located immediately downstream of the control ports.
Other fluidic oscillators may be used in practicing the invention.